I am thinking about building a new desktop and was looking for some recommendations. I am pretty sure I wanna go with an i7 920 and NVIDIA card. My budget is about $1500, I am not really concerned about cutting it cheaper than that, unless the price to performance ratio is far out of line. I already have a nice 24" LCD monitor, so I won't need one of those.

I have a NAS, so performance > storage capacity. Also, my preference is to do all my business with newegg, they have always been reliable for me, and I find it easier for everything to come from the same place.

If you're writting and transfering a large amount of data, that is a sizeable increase over what your average user and gamer would do, then a RAID-0 would be worth it. Like what was stated above, you add twice the risk of data loss. If one HDD goes, you're done. What's the alternative?